PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

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PostGIS - How to calculate linestring length from WGS84 after transforming from OSGB 36

I am having problems getting lengths from multilinestrings after transforming data from EPSG:27700 - OSGB 1936 / British National Grid to EPSG:4326/ WGS 84. I'm doing this conversion to import a ...
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1answer
39 views

pgRouting not returning node with correct z-value

have an issue with pgRouting that I've modified to consider multi-floor indoor areas. I've created a mock floor plan of any typical hotel. I copied the floor plan and assigned a different z-value to ...
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2answers
51 views

How to get ST_MakeLine ready for QGIS?

CREATE VIEW new_line AS SELECT point1.gid, ST_MakeLine(point1.geom, point2.geom) FROM point1, point2 WHERE point1.gid = point2.gid; It's possible to load the layer but QGIS says 'There is no entry ...
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1answer
53 views

find the population density of some points in qgis/postgis

I have the tiger census data of population density in each block group. I also have a different kind of data: traffic accident data, where an accident has a lat/lon pair. My goal is to find the ...
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2answers
43 views

PostGIS : ST_Contains doesn't work after ST_FlipCoordinates

I'm using postGis in a personal project, mainly to determine if a point is inside a Polygon. I realized I was using lat/long instead of long/lat for creating my polygons and using ST_Contains. Thus i ...
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1answer
64 views

What is a MultiPolygonZM geometry type?

My imported shapefiles (shp2pgsl) have the geometry type "MultiPolygonZM". geom geometry(MultiPolygonZM), What is this type of multi polygon? I can't find any useful information.
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51 views

raster2pgsql error

I am attempting load ~500 rasters in a PostGIS table. They are .Hdr/.dat files. I am using raster2pgsql. I am able to load the first 260 rasters, but the remaining rasters fail with the following ...
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1answer
68 views

How to create a sequence for a table which was created by selecting data from another table?

I have created a new table by selecting data from an existing table: CREATE TABLE polygon2 AS SELECT gid, geom FROM polygon1; CREATE SEQUENCE polygon2_gid_seq; SELECT SETVAL('polygon2_gid_seq', ...
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1answer
55 views

How to compute equality of polygons in PostGIS independently of their orientation?

I tried some functions in postgis. Scope of work, get the equality of two shapes, independently of their orientation in the space. I detect the shapes from autocad and of course in lifetime of a ...
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1answer
48 views

trigger postgis and dump qgis 2.8.2

I created a trigger that checks if geometry is valid on insert and update. create or replace function check_geom() returns trigger as $$ begin --insert a polygon IF st_isvalid(new.geom) = 'f' ...
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45 views

Reprojecting in Postgis

I try to reproject a layer in PosGIS using statement: UPDATE <table> SET geom=ST_Transform(geom, 3857); leading to error message: ERROR: transform: couldn't project point (574415 6.22508e+006 ...
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1answer
156 views

Polygon area calculation in Ruby (on Rails, rgeo, PostGIS and GEOS) in sqare meters

In a Ruby-on-Rails application, I need the area in square meters (or any other surface measure, be it ares, hectares, square kilometers, but not in pseudo surface measure like square degrees) of a ...
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1answer
75 views

St_Difference between raster and vector using PostGIS

I want to calculate the difference between a raster and vector layer, I used this querie but it's so slow and I don't know if it's right or not. I'm not using st_difference because it only support ...
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41 views

What is the fastest way to select oldest, unique geometry from a table containing duplicates in PostGIS?

I have an output from an ArcPy arcpy.Union_analysis operation and for the overlap polygons that were created I need to select out the oldest feature (along with the attributes). The result is 75740 ...
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32 views

Error in osm.xml while generating the output xml for tile server using generate_xml.py

I'm setting up my own tile server using PostGreSQL, PostGIS extension, mapnik and osm2pgsql. While trying to generate the xml by using the command: E:\>python generate_xml.py download_osm.xml ...
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18 views

Add individual fields to delete-log-trigger when deleting PostGis-Objects via QGis

I am using a PostGres Database with PostGis extension (on Windows). QGis serves as a client to access (visualize and edit) certain database-tables. I need to create a delete-log-table that saves all ...
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72 views

How to develop a QGIS plugin to fully run spatial queries with PostGIS?

I am developing a QGIS plugin that fully runs spatial queries with PostGIS. I developed all spatial queries which need some adjustment. I am looking for some resources or documents to know how to ...
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20 views

Issue when creating points with php and entering them in postgis

I pass some data to a postgis table defined as: CREATE TABLE categoriesdata (id serial NOT NULL, name character varying(200), geom geometry(Point,4326), CONSTRAINT obj_geom_pkey PRIMARY KEY ...
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1answer
43 views

Enabling: Raster and Topology

I'm new to GIS and tile servers. I've installed TinyOWS pretty successfully except for what looks like to be some dependency issues. I have installed PostGIS and also PostgreSQL. PostGIS is supposed ...
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13 views

Recentering a tiled raster table in PostGIS?

Does anyone know a nice and easy way to recenter a tiled raster table in PostGIS? By recentering I mean that I have a raster that is centered on the Pacific, but I need to recenter it on ...
2
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1answer
29 views

How to obtain WGS84 or Projected Bounds for given EPSG in postgis?

On the http://spatialreference.org, for almost all SRS are definied WGS84 Bounds and Projected Bounds. How to obtain this bounds from postgis? Spatial_ref_sys does not contains this information.
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19 views

Mirrored shape in postgis

I'm troubling with save of shapes in db. The shapes are steel sheet cuts, with may be holes, therefore are collections. I decided to solve to my self the problem, to allow the easy exportation between ...
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23 views

Calculating slope from elevation returns hole when using ST_Slope in PostGIS

I have rasters from the National Elevation Dataset loaded into a PostGRES database and am using the built-in function ST_Slope to calculate the slope. However these contain many holes where there is ...
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37 views

Optimize PostGIS query, ST_Intersects - Raster and Geom

I am trying to run a spatial query between two tables. Table one (prism_ppt_monthly - see below for details) is monthly precipitation data. Table two (usgs_basin_boundary - see below for details) are ...
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2answers
82 views

Find all polygons containing points specific criteria

I have searched for a bit, but couldn't find an answer for my question. So I have two tables (PostGIS), one containing points, and the other containing polygons. Right now i have this query for ...
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65 views

PostGIS for GPX analysis

I have GPX trails of vehicles/bikes of a particular city. Meaning, lat/lon, timestamp of bike trails from where a particular bike started and ended at different hours of the day. I have sets of these ...
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42 views

Make a line from a set of GPS points close to a specific GPS point with PostGIS

I have to develop a map-matching algorithm. At the moment I only match GPS points with the closest road segment. I'm looking for a way to compare the directions between a GPS point and a road to ...
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1answer
110 views

PostGIS Best Practices with thousands of entries

I'm creating a PostGIS database which will hold thousands of different shapes (imported from Shapefile, GeoJSON, etc), and they'll stay there and be queried over time. Do I need to create a ...
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27 views

MultiPatch Shapefile import into PostGIS Database

I have geometry of buildings in Shapefile MultiPatch format. I want to import it into PostGIS database in the same format. Is that even possible? If yes, then how?
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34 views

GeoDjango and bug with bounding box query

Just some context first, I have a postgres database with PostGIS extension, running under a GeoDjango wrapper. I have a weird bug that hopefully someone can shed some light on. I'm running a query ...
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1answer
36 views

How to check if a node is in route computed with pgRouting?

I'm new to the GIS system and I'm following the pgRouting workshop. I've imported the locations of nodes (points, highway=street_lamp) using osm2pgsql. now I'm calculating a few paths between two ...
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1answer
60 views

Why can't I import my shp file into a postgis database with SRID 102631 using shp2pgsql?

Hi I have been trying to figure out the reason shp2pgsql isn't working when I try to import a shapefile with SRID=102631. I've had no problems with other SRIDs. For all shapefiles in 102631, I get ...
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1answer
57 views

Where to store lat/lon data with additional informations?

I have huge database of lat/lon GPS coordinate points. For every point, I have several other variables (height, surface type, temperature, pressure...). Also, data will be changed every day and old ...
3
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1answer
26 views

PostGIS - interfacing with CADCORP 7.1 and QGIS - user 'postgres' can import, but no other roles can

I'm new to PostGIS (reasonably) - but I'm plagued with one on-going problem: I'm able to access PostGIS from various GIS systems using the main 'postgres' user. Using a newly created user ...
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1answer
26 views

Importing map information with osm2pgrouting

I'm importing the cartography of Spain with osm2pgrouting. I want to import address information, that is, the tag addr = *. I modified the file mapconfig.xml follows: <type name="junction" ...
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13 views

OpenGeo Suite 4.0.1 Activating SSL for remote connection

I have installed OpenGeo Suite 4.0.1 on my Windows 7 OS and created a spatially database. Now i want to connect to my database remotely but then it seems like i have to generate a self-signed key. i ...
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16 views

How to specify the new layer type in writeOGR{rgdal}?

There is a task that we copy some polygons into postgis using rgdal package. I noticed postgis is strict with geometry type so that the new multi-feature layer type must be specified. I tested the ...
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0answers
64 views

Field Collection App for Geoserver or Any OS GIS Server

I am looking for a mobile app/interface for field data collection and mobile editing of GIS data that relies/syncs back to some type of GIS server or database. I am aware of Fulcrum and AmigoCloud, ...
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1answer
27 views

PostGIS Topology Requires Admin

I am running PostGIS on an Ubuntu server. I am able to add the Topology extension via CREATE EXTENSION, but when I try to use it as anything other than an admin I am denied permission. I ran GRANT ...
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38 views

QGIS: Edits in attribute table are not updated in Postgis database. Why?

As the title say. I edit values in the attribute tables of my QGIS project but there is no update to the database. I refreshed in QGIS as well as the database. What else do I need to do?
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1answer
55 views

Displaying raster tiles from OSM data stored in a postgis server

I have been recently tasked with setting up a raster tile server that serves tiles from data pulled from a postgis store. I have managed to get a vector tile server up and running but I'm stuck on ...
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51 views

H2GIS and POSTGIS

i use PostGIS and H2GIS and i have tested ST_Transform function on both systems: SELECT ST_AsText( ST_Transform( ST_GeomFromText('POINT('||to_char(5873455.6,'9999999.99')||' ...
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1answer
35 views

Rectangle Appears Distorted on Map

When displaying two features, a polygon a (see geoJSON) and its minimum bounding rectangle b (see geoJSON), I get the following result when viewing on geojson.io: The minimum bounding rectangle ...
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1answer
100 views

Split a table of Multi/Linestrings into Unique Linestrings

Is there an efficient way to split a table of Multi/Linestrings that overlap() and touch() into unique Linestrings (note: creating edges using topology is going very...very...very slow). Here is ...
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35 views

Converting NAD 83 to WGS 84 in PostGIS

My question is about the best way to convert from NAD 83 to WGS 84 in PostGIS. I have a PostGIS DB containing National Elevation Data rasters. The rasters are in NAD 83 and I would like to convert ...
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1answer
38 views

PostGIS: Perform a Spatial Join only joining the intersecting polygon with the maximum value

I'd like to perform a spatial join using PostGIS. I've got table_A containing 80.000 entries and table_B containing roughly 1.500.000 entries. The entries in table_B have a column "number". My goal ...
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12 views

How to render visualizations for geospatial objects (the way QGIS does it) on web interface for end users, from PostGIS database? [duplicate]

I have existing geospatial objects in PostGIS. I can visualize it using QGIS. But I want to render these visualization on a web-interface for my users as a result of some queries in the database. I ...
2
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1answer
66 views

Draw line with lon, lat, distance and azimuth

I have table in PostGIS with lon, lat, distance and azimuth columns. I want to make Geoserver draw a line through first point with given length and direction. I can turn lon and lat to geometry in ...
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2answers
60 views

geometry from relations - osm

Can someone show me the relevant documentation for relationships between tables? I'm trying to get the geometry for an entry from the relations table but I'm unable to pick out the right information ...
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1answer
43 views

Moving file flat-nodes.bin from an osm2pgsql import

I'm running PostgreSQL 9.4 and osm2pgsql 0.82.0 on Ubunt 14.04 (64bit). I'm new-ish to postgres and less new to OSM. My goal was to import the planet file. Unfortunately, when I started the import, ...